Multi‐omics Analysis Reveals the Correlation of Gut Microbiota and Metabolites With Thalidomide Treatment for Chemotherapy‐Induced Nausea and Vomiting in Small Cell Lung Cancer

Small cell lung cancer (SCLC) is a highly aggressive malignancy, and chemotherapy frequently causes nausea and vomiting, which can impair treatment tolerance. Because thalidomide (THD) has shown potential clinical benefit in alleviating nausea and anorexia, we investigated whether its effects might be associated with changes in gut microbial composition and metabolite profiles. Fecal samples were collected from patients with SCLC and categorized into THD-treated and control groups. Metagenomic sequencing and nontargeted metabolomic profiling were performed to characterize microbial composition and metabolic signatures. THD treatment was also associated with higher microbial alpha diversity and increased abundance of genera such as Eubacterium and Prevotella. Metabolomic analysis identified several differential metabolites, including hydrogenated MDI, becocalcidiol, β-octylglucoside, and azelaic acid. Collectively, these findings suggest that the gut microbiota-metabolite axis may be associated with the potential effects of THD on CINV and anorexia in patients with SCLC. The identified microbial taxa and metabolites may serve as candidate biomarkers or potential therapeutic targets, although further validation in larger studies is necessary.